Explain ABO blood group system in human being with a suitable chart.

Explanation

ABO blood group : This system was given by Karl Landsteiner.
(a) Antigen : These groups are based on two antigens present on the membranes of RBC's namely antigen A and antigen B. A person may have neither of them or one of them of both of them.
(b) Antibody : It is `lambda`-globulin present in blood plasm, so it is called plasma factor. There are two types of antibodies a and b. A person may have neither of them, one of them or both of them. Antigen A and antibody a and antigen B and antibody b are incompatible to each other and cause self clumping. On the basis of this four blood groups are recognised. Person with blood group O is called universal donor as it has no antigen and can donate blood to any person. Person with blood group AB is called universal recipient as it has no antibody in their plasma so can receive blood from any blood group.